采用大钢锭生产特厚桥梁钢板Q345qDZ35的实践

南阳汉冶特钢公司通过采用KR脱S、LF精炼、VD真空处理、模铸保护浇铸等手段确保钢水纯净度以及通过采用＂高温、低速、大压下＂轧制、轧后控冷、热处理等手段确保钢板内部组织细密、均匀,成功研发出厚度达130mm的Q345qDZ35特厚桥梁板。性能检测结果表明,屈服强度、抗拉强度平均富裕量达30MPa以上、伸长率平均富裕量达7.0%以上,-20℃低温冲击平均富裕量达100J以上,Z向拉伸平均富裕量达40%,各项性能均满足特厚桥梁钢的使用要求。

Production practice of super thick Q345qDZ35 steel plate with large ingot for bridge

Super thick bridge steel plate Q345qDZ35 with a thickness of 130 mm was successfully developed in Nanyang Hanye Special Steel Co.Ltd.The production processes include: KR desulphuration,LF refining,VD vacuum treatment and protective casting of ingot casting to ensure molten steel purity,high temperature low speed heavy reduction rolling,subsequent controlled cooling and heat treatment to obtain fine and even internal structure.The performance testing results showed that the average margin of yield strength and tensile strength,elongation percentage,low temperature impact energy at-20 ℃ and Z direction tensile strength was above 30 MPa,7.0 %,100 J and 40 %,respectively.The mechanical properties can satisfy the application requirements of super thick bridge steel.